# The Gaseous State Chapter 10. Kinetic Theory Kinetic energy is the NRG of motion The Kinetic Theory states that all particles of matter are in constant.

## Presentation on theme: "The Gaseous State Chapter 10. Kinetic Theory Kinetic energy is the NRG of motion The Kinetic Theory states that all particles of matter are in constant."— Presentation transcript:

The Gaseous State Chapter 10

Kinetic Theory Kinetic energy is the NRG of motion The Kinetic Theory states that all particles of matter are in constant motion

Assumptions of Kinetic Theory in relation to gases: 1.Gases are composed of small, hard spheres with an insignificant volume 2.They are far apart with empty space in between

3. There are no attractive or repulsive forces between the particles 4. The particles move rapidly and are in constant motion 5. They travel in straight paths independently of each other

6. Gases fill their container indefinitely (they will expand) 7. Only change direction after colliding with something else 8. All collisions are perfectly elastic – no energy loss

The kinetic theory is helpful in explaining gas pressure Gas pressure: force exerted by a gas on its container An empty space with no particles = vacuum = no pressure

Atmospheric pressure – the pressure of air around earth – dependent on the weather Barometers measure air pressure

SI Unit of pressure is the pascal (Pa) At sea level, Atm. Pressure is 101.3 kilopascals (kPa) mmHg and atmospheres (atm) are older units of pressure 1atm = 760mmHg = 101.3kPa

The standard conditions to relate measured values to are 1atm (101.3kPa) and 0 o C, or STP – this is important when discussing gases and gas pressure

When a substance is heated, the particles store some of the absorbed NRG (potential) but the NRG not stored increases the speed of the particles, the average kinetic NRG & the temperature

The actual particles have a wide range of kinetic energies – but temperature is the average kinetic energy At high temperatures, there is a wider range of kinetic NRGs

As a substance cools, the particles lose energy & slow down Absolute Zero (0K, -273 o C) theoretical temperature when no movement occurs = no NRG